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Related papers: Grain Alignment by Radiative Torques

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The recent detection of interstellar polarization in the solid CO feature near 4.67 micron shows that CO-mantled grains can be aligned in cold molecular clouds. These observations conflict with a theory of grain alignment which attributes…

Astrophysics · Physics 2015-06-24 A. Lazarian , W. G. Roberge

Paramagnetic alignment of non-spherical dust grains rotating at thermal velocities is studied. The analytical solution is found for the alignment measure of oblate grains. Perturbative approach is used for solving the problem. It is shown…

Astrophysics · Physics 2009-10-28 A. Lazarian

The linear polarization of thermal dust emission provides a powerful tool to probe interstellar and circumstellar magnetic fields, because aspherical grains tend to align themselves with magnetic field lines. While the Radiative Alignment…

Magnetic fields are ubiquitous in the universe and are thought to play an important role in various astrophysical processes. Polarization of thermal dust emission from dust grains aligned with the magnetic field is widely used to measure…

Astrophysics of Galaxies · Physics 2024-02-20 Thiem Hoang , Bao Truong

We study the physical processes inducing the alignment of the grain axis of maximum inertia moment with the angular momentum (${\bf J}$, i.e., internal alignment) and of ${\bf J}$ with the magnetic field (i.e., external alignment) of very…

Astrophysics of Galaxies · Physics 2022-11-30 Thiem Hoang , Le Ngoc Tram , Vo Hong Minh Phan , Nguyen Chau Giang , Nguyen Thi Phuong , Nguyen Duc Dieu

Dust polarization depends on the physical and mechanical properties of dust, as well as the properties of local environments. To understand how dust polarization varies with grain mechanical properties and the local environment, in this…

Astrophysics of Galaxies · Physics 2020-06-17 Hyeseung Lee , Thiem Hoang , Ngan Le , Jungyeon Cho

Multiscale phenomena which include several processes occuring simultaneously at different length scales and exchanging energy with each other, are widespread in magnetism. These phenomena often govern the magnetization reversal dynamics,…

Materials Science · Physics 2009-10-31 V. V. Dobrovitski , M. I. Katsnelson , B. N. Harmon

Atacama Large Millimeter/Submillimeter Array (ALMA) has revolutionized the field of dust polarization in protoplanetary disks across multiple wavelengths. Previous observations and empirical modeling suggested multiple mechanisms of dust…

Solar and Stellar Astrophysics · Physics 2024-07-30 Nguyen Tat Thang , Pham Ngoc Diep , Thiem Hoang , Le Ngoc Tram , Nguyen Bich Ngoc , Nguyen Thi Phuong , Bao Truong

The polarization of starlight and thermal dust emission, resulting from non-spherical grains aligned with the interstellar magnetic field (B-field), act as a powerful tool to trace the B-field morphologies and strengths in molecular clouds…

Astrophysics of Galaxies · Physics 2026-05-26 Saikhom Pravash

We present extensive calculations on the efficiency of grain alignment by the Davis-Greenstein mechanism. We model the grains as oblate spheroids with arbitrary axis ratios. Our description of the grain dynamics includes (i) magnetic…

Astrophysics · Physics 2010-10-27 W. G. Roberge , A. Lazarian

We propose a semi-discrete numerical scheme and establish well-posedness of a class of parabolic systems. Such systems naturally arise while studying the optimal control of grain boundary motions. The latter is typically described using a…

Analysis of PDEs · Mathematics 2018-10-26 Harbir Antil , Ken Shirakawa , Noriaki Yamazaki

Dust polarization induced by aligned non-spherical grains acts as an important tool to trace the magnetic field (B-field) morphologies and strengths in molecular clouds and constrain grain properties and their alignment mechanisms. The…

Astrophysics of Galaxies · Physics 2026-03-03 Saikhom Pravash , Thiem Hoang , Archana Soam , Qi-Lao Gu , Tie Liu , Pham Ngoc Diep , Le Ngoc Tram , Nguyen Bich Ngoc

The properties of interstellar grains can now be defined by a rapidly growing wealth of observational data. We rely upon models to combine these data with unobserved properties such as the size distribution of grains, their structure and…

Astrophysics · Physics 2007-05-23 Adolf N. Witt

Dust grains are important in various astrophysical processes and serve as indicators of interstellar medium structures, density, and mass. Understanding their physical properties and chemical composition is crucial in astrophysics. Dust…

We study the internal and external alignment of carbonaceous grains, including graphite and hydrogenated amorphous carbon (HAC), in the interstellar medium (ISM) within the RAdiative Torque (RAT) paradigm. For internal alignment (IA), we…

Astrophysics of Galaxies · Physics 2023-01-20 Thiem Hoang , Vo Hong Minh Phan , Le Ngoc Tram

A quantitative analysis of grain alignment in the filamentary dark cloud L1755 in Ophiuchus is presented. We show, that the observed decrease of the polarization to extinction ratio for the inner parts of this quiescent dark cloud can be…

Astrophysics · Physics 2008-11-26 A. Lazarian , Alyssa A. Goodman , Philip C. Myers

Dust clouds are ubiquitous in the atmospheres of hot Jupiters and affect their observable properties. The alignment of dust grains in the clouds and resulting dust polarization is a promising method to study magnetic fields of exoplanets.…

Earth and Planetary Astrophysics · Physics 2021-08-24 Thiem Hoang , A. Lazarian

Experimental grain growth observations often deviate from grain growth simulations, revealing that the governing rules for grain boundary motion are not fully understood. A novel deep learning model was developed to capture grain growth…

The optical and near-infrared (OIR) polarization of starlight is typically understood to arise from the dichroic extinction of that light by dust grains whose axes are aligned with respect to a local magnetic-field. The size distribution of…

The polarization of starlight and thermal dust emission from aligned non-spherical grains provides a powerful tool for tracing magnetic field morphologies and strengths in diffuse interstellar medium to star-forming regions, and…

Astrophysics of Galaxies · Physics 2025-07-11 Saikhom Pravash , Thiem Hoang , Archana Soam , Eun Jung Chung , Pham Ngoc Diep , Nguyen Bich Ngoc , Le Ngoc Tram